remove explicit python version to avoid conflict with virtualenv
remove explicit python version to avoid conflict with virtualenv

chubbymaggie/angr,f-prettyland/angr,schieb/angr,iamahuman/angr,tyb0807/angr,f-prettyland/angr,angr/simuvex,axt/angr,chubbymaggie/angr,angr/angr,schieb/angr,tyb0807/angr,axt/angr,angr/angr,iamahuman/angr,axt/angr,f-prettyland/angr,schieb/angr,angr/angr,iamahuman/angr,chubbymaggie/angr,tyb0807/angr